Genetic variants and environmental factors like PM2.5 exposure may increase asthma risk in susceptible individuals

This narrative review explores the interplay between genetic variants and environmental factors in asthma. The scope includes smoking, stress, obesity, diet, occupational exposure, respiratory viral infections, early-life allergen exposure, low physical activity, and air pollution such as PM2.5. Currently identified genetic variants explain only part of asthma heritability, indicating a significant gap in understanding the genetic contribution to the disease.

Exposure to PM2.5 may increase the risk of asthma, particularly in genetically susceptible individuals. The review highlights that specific effect sizes, absolute numbers, and p-values were not reported in the source material. Consequently, the magnitude of risk associated with these environmental factors remains qualitative rather than quantitative.

The authors discuss the complex nature of asthma etiology without providing specific adverse event rates or tolerability data. Limitations regarding the study phase and setting were not reported. The review suggests that while genetic and environmental factors are linked, the precise mechanisms and magnitudes require further investigation. Practice relevance and funding information were not reported in the source text.